In wireless networks, such as a wireless cellular network, network operators normally deploy a minimum amount of bandwidth to provide service coverage to end users for a designated geographical area. The aforesaid minimum amount of bandwidth is sometimes referred to as the coverage carrier. As user demand increases, the network operators add additional bandwidth to increase capacity to meet the demand. The additional bandwidth is sometimes referred to as the capacity carrier. To meet still more user demand, more than one capacity carriers can be additionally deployed. The capacity carriers can be arranged to cover the entire geographical area, or alternatively, on a site-by-site basis. For the latter, additional coverage zones, sometimes referred to as hot spots, are created to provide coverage extension and capacity. The inclusion of the hot spots results in a non-uniform, multi-carrier deployment communication network.
Hot spots can be created in accordance with demand as aforementioned. Nevertheless, these hot spots are often served with more than one carrier frequencies. As such, user devices need to be capable of transitioning among the different frequencies. Heretofore, there has not been any satisfactory scheme to provide any seamless transitions. For example, in a typical inter-frequency handoff by a single-carrier device, it requires a break of the existing communication session carried by one frequency before the communication device is able to resume the communication session carried by another frequency. Such transitions can result in loss of data. Furthermore, the interrupted transitions may negatively impact user experience.
Accordingly, there is a need to provide a seamless transition from one frequency to another in a multi-carrier communication system.